Data collection system having plural channel storage of sequential signals



P. T. STINE DATA COLLECTION SYSTEM HAVING XDLURAL CHANNEL STORAGE OF SEQUENTIAL SIGNALS LLI E Jan. 16, 1968 p, T, SNNE 3,364,466

DATA COLLECTION SYSTEM HAVING PLURAL CHANNEL STORAGE OF SEQUENTIAL SIGNALS Filed Nov. 27, 1963 2 Sheets-Sheec 2 OUTPUT INVENTOR PAUL Z' STI/VE ATTORNEY rm T.

States of America as represented by tbe'Secretary ot circuitry to store data, are mitter.

DATA COLLECTION SYSTEM HAVING PLURAL CHANNEL STORAGE F SEQUENTIAL SIGNALS Stine, Morningside, Md., assigner to the United the Navy y Filed Nov. 27, 1963, Ser. No. 326,642

y `4`Clslms. (Cl. 340-147) ABSTRAC'I` OF THE DISCLOSURE Telemetering system. for short duration phenomena. Plurality of channels, which include sensors and ditferent arrangements of sequenced, peak holdingand intergrating sequentially connected to trans- 'lhe invention described herein may bemanufactured and used by or lfor the' Government of the `United States of America for governmental purposes withoutthe payg mentof any royalties thereon or therefor.

This invention relates to a telemetering system land more particularly to a4 telemetering system for sensing extremely short duration phenomena in an environment which prohibits broadcasting at. the time of the data occurrence. v

lt is often desirable toobtain information concerning events which occur while the vehicle containing the sensor and telemetering transmitter is located either at" a great similar andare sequentially gated to receive later signals 3,364,466 Iia'tel'tted Jan. 16, 19168v me v ' In brief. this invention is a system which is normally in an unenergized condition and which is activated by-a. sensor signal resulting from a first-event. The system includes two or more channels which'are sequentially gated in chronological order to receive. the signals from a sensor or sensors. The sensor signal representing the first event,

which is used to activate the system, is delayed as required for the initiating the gating and system activating processes and is then applied to the tirst channel wherein the signal is integrated and its peak measured and this information stored. All of the remaining channels, if more than one other channel is required, are functionally from the sensor or sensors. The gating periods may, of course, be different for the various channels. The other channel, or channels, periodically sample the amplitude distance from `the receiver or in a highly ionized area wherein electromagnetic propagation Awill not be support--y ed. Many of these events are of such short duration that the desired information cannot be transmitted by conventional practices because of telemetering bandwidth`limitations. y u

-Previou's systems which have been developed for the purpose of' obtaining information under the conditions described, .have for the most part included magnetic storage and playback, and have not been entirely satis- 1 factory because of their bandwidth limitations. Other conlsiderations relating to previous systems are their complexityand an accompanying unreliability, electrical power requirements.

'An object of the present invention is the provision of an improved system for sensing, storing andvtelemetering data concerning short duration phenomena'which may be nonrecurrent. v

It is another object of this invention to provide an improved system with greatly decreased bandwidth limitations capable of processing data pulses in the order of a few microseconds which may occur during periods of size, weight and `temporary radio isolation. .4

A further object of the present invention is to .provide asystem which is activated by a lrst event; senses, stores i vand later transmits data concerning the amplitude and duration of the first event and, at scheduled periods after .now made to the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a block diagram of an embodiment of the invention, and

FIG. 2 shows a circuit suitable for use as the peak read and hold and the integrate and hold circuits of the inf lof the respective signal received andstore this informay tion. The information stored in all the channels islater removed by a commutator and transmitted by tional telemetering transmitter.

In the embodiment of the invention illustrated in FIG.l

l, a sensor 10, which produces au electrical signal representative of a condition about `which information is desired, is connected to a pulse generator 11 and through delay line 12 to input, or channelizing gate 13 of channel 1. The function of delay line l2 is to withhold the initial sensor signal from gate 13 for a period of time sufficient for pulse generator 1l, which is energized by the initial signal from sensor 10, to initiate a pulse which opens gate 13 and thereby allows the signal from sensor l0 to reach the integrate and holdcircuit 14 and the peak measuring and hold circuit 15. FIG. 2 illustrates a circuit suitable y for use as the integrate and hold circuit 14 and the peak measuring and hold circuit 15 and the other holding ciry' cuits of this invention. While FIG. 2 will be later de-.

scribed in more detail, for the present it is sulicient to functionally vdescribe circuit 14 as integrating the initial signal from sensor 10 and holding iny storage the inteizing vgate 13a of channel 2, thereby allowing a signal from either sensor 10 or'sensor 10a, vasA determinedby switch 16, to reach the sampling gates 17, 17a which are illustrated as being three in number but could obviously be a largernumber as desired. The samplingv gates 17, 17a 17u are sequentially opened by the tapped delay line 18 which is energized by a pulse ob tained by conventional means from the leading edgeof the pulse from pulse generator lla. Peak measuring and hold circuits 19, 19a 19u are connected to sampling gates 17, 17a 11m-thereby receiving to measure and storelthe peak value of sequential samples of the sensor signa v Pulse generator 11n is connected to pulse generator 11a and is keyed to the trailing edge of the pulse from generator 11a to supply a pulse to open the input, or channelizing gate l3n of channel 3, thereby allowing a signal from either sensor 10 or sensor-10u, as determined by switch 1in. to reach the sampling gates 20, 20a

20u. which are illustrated as being three in number but could be a larger number as desired. lt is also obvious louter, datation are preferable n s deny une. The muni-1 -i e the sampling gates 20a 20u. Peak measuring and hold circuits 22', 22a 22u are connected to sampling gates 20, 20a .2011. thereby receiving to measure and -hold the peak'value of sequential ysamples of the sensor signal.y

Commutator 23 is `connected to the output of holding circuits 14', 1s, 19, 19a un, zz, zza zzn and functions to sequentially connect the holding circuits tov transmitter 24 which may be any one of the several, suitable well known types of telemetering transmitters, such as pulse width, PM, FM, FM/FM, etc. The commutator 23 is l also conventional in nature and may be either electronic or mechanical, continuously running or delayed start after triggering by pulse generator l1, etc. The speed.

of commutator 23, must of course, be

compatible with the limitations of transmitter; 24.-

' The operationof the system illustrated in FIG. l will now be described in the function of gathering data relating to tlrree `chronologically predictable events which occur, not necessarily recurrently, at a time when radio transmission is temporarily not advisable. Such events could occur, for example, in such diversified circumstances as when a probe missile is being used to gather data in the highly ionized area near a nuclear blast, when a satellte is far "from a telemetering receiving station and when abody is surrounded byan ionized sheath on reentering the atmosphere. y

' The. system of FIG. l is in an unenergired condition, requiring little or no electrical power, until the sensor l produces a signal representative of an extremely short duration, high magnitude first event. This signal triggers ypulse generator ll, which produces a pulse that is effective to maintain the input, or channelizing gate 13 in an open t condition for a period of time, such as 150 microseconds.

As a--finite time is required for the initiation of the gating and system actuating processes, the signal from sensor l0 is ,passed through delay line l2 where it is delayed a short` time, typically 8 t microseconds, before passing through input gate 13 into channel 1. In channel l the t signal representative of the first event is integrated, and

the integral value stored, by circuit 14 and the peak value 'of this signal is measured and stored by circuit 15. It is to be noted that-for extremely short duration, high amplitude signals, obtaining information concerning the peak valueand energy'integral is considered to be more feasible than `attempting to reproduce the signal shape.

The pulse generator 11a is triggered by the trailing edge of the 150 microsecond pulse produced by pulse generator 1l.- Generator lla produces a pulse that is v effective to maintain input gate'13a inv an open condition for a period of time, such as 5 0 microseconds. In this J nel .2 by passing a pulse, typically of 2 microsecond duration obtained by conventional means from the leading edge of the 750 microsecond pulse from generator lla,

through tapped delay yline 18. TheA taps vfrom delayA line 18 unconnected to sampling gates 17, 17o 17u,

`which are typically in number. This arrangement is effective to sequentially openA these sampling gates and 19, 19a 19u which measure and hold the amplitude of the sequential samples. These-samples must, of course,

be sufficient in number to allow a plotted reconstruction of the signal shape.

Channel 3 is functionally s imilar'to channel 2 and is :used to obtainand store information relatingto a third event which is of relatively longer duration. The vpulse generator 11n is triggered by the trailing edge of the 50 micro second pulse produced by pulse generator 11a. Generator 11n produces a pulse which Amaintains input, or channelizing gate l3n in an open condition for a relatively longer period of time, such as 30 milliseconds. During this period the predictable third event occurs'and is sensed by sensor 10, or sensor 10u as desired. The resulting signal is passed through input gate 13u into channelv 3. In this channel, sampling gates 20, a 20u are sequentially opened by multivibrators 21, 21a 21u, the first of which is keyed to the leading edge of the millisecond pulse from generator lln. The remaining multivibrators 21a 2ln are keyed to the trailing edge of the pulses from the preceding multivibrators. This arrangement is ef= Yfective to-sequentially open sampling gates 20, 20a

20u and pass sequential samples of the sensor signal to cir-1 cuits 22, 22a 22n which measure and hold the amplitude of the sequential samples.

After a predictable period of time, conditions will be come favorable for radio transmission, such as when the satellite approaches a receiving station or the transmitter is no longer located in an ionized medium. At that "time,4

the commutator, if not continuously running, will be ener gized by conventional, built-in, programming apparatus, and will function to sequentially withdraw and-broadcast the information stored in the holding circuits by transmit ter 24. The information received by the ground station will include a signal representing the energy integral of the first event, a signal representing the magnitude of the first event and two sequences, each of ten signals, suit-able for plotting a reproduction of vthe shape of the sensor signals associated with the second and third events.

By using a commutator speed such that the signal samples are withdrawn over a longer period of time than the original occurrence, typically 500 times longer, the signal samples in channels 2 and 3 can be used to reconstruct the wave shapes of sensorsignals relating to shortdura.-

tion events. Such short duration wave shapes cannot be accurately transmitted and reproduced over conventional telemetering links. y

FIG. 2 shows a circuit suitable for use as the integrate y land hold circuit 14 and as the peak measuring and hold circuits l5, 19 and 22. In this circuit the plates of thefour tubes 30, 3l, 32 and 33 are connected to a source of plate present in series with the storage capacitor 34. A resistor 'pass sequential samples -of the sensor signal to circuitsv 35 is connected in series with capacitor' 34 if the circuit is to be used as the integrate and hold circuit 14, the

values of capacitor 34 and resistor 35 vbeing chosen so thatv their time constant is at least five times as long as the longest input pulse expected to be integrated. The resistor 35 rs not included in the circuit if it is to be used as a peak measuring and hold circuit 15,-19 or 22. The charge on storage capacitor 34, .which is related either to the integral or peak of the input signal, is connected through the parallel connected circuit of resistor .36,and capacitor 37 to lthe grid of tube 32. This tube is connected as a cathode follower and functions to prevent loading by the output loadrmpedance. The resistor 38 is connected as the cathode load of tube 32 and provides the grid signal to tube 33 which is connected as a cathode follower'in the `output stage of the circuit. The output, a D.C. voltage proportional either to the integral or' the peak value of the input signal, is produced at a low impedance level across the .cathode load resistor 39 of tube 33.v

are possible in the light ofthe above teachings, It is, therefore, lo be understood, that within thescope of the appended claims, the invention may be practiced otherwise than as specifically described.

What is'claimed is: v

l. A system for gathering data relating to shortduration events, the chronological sequence of which is predictable and which occur under conditions wherein transmission of the data at a later time is desirable, comprising:

sensor means which produce electrical signals repre sentative of the events being investigated;

a plurality of channels operatively associated with said sensor means wherein each of said channels includes Lstorage means for receiving and storing a signal; gating means operatively associated with said sensor means and connected to said plurality of channels and adapted to be energized by the trst of said electrical signals to operatively connect in an ordered chronological sequence, related to the predicted sequence of events, individual ones. of said plurality of channels to said sensing means;

a transmitter and a commutator connected to said transmitter and to said storage means to sequentially connect said storage means to said transmitter.

2.v A system as set forth in claim l lwhereina tirst channel includes an integrate and hold circuit and a peak measuring and hold circuit. i

3. A system as set forth in channels includes a yplurality of storage means and control means which sequentially `connect said plurality of storage means to individually receive sequential samples of f the sensor signal received by said channel.

4. A system for gathering data for transmission at a later time comprising:

claim l wherein one of said events and including gating means operatively assoi ciated with storing means and multivibrator means wherein longer duration signals are sequentially sampled at approximately 3 millisecond intervals by said gating means and said'samples are stored by said storing means under the control of said multivibrator means and; v l

transmitter and a commutator connected to said t transmitter and to said storage means to sequentially connect said storage means to said transmitter.

References Cited UNITED STATES PATENTS 2,933,689 4/1960 JohttSOtl 328-151 X 3,059,228' 10/ 1962 Beck et a1. f. 340--147 3,063,014 r ll/,l9v62 Shanks 328-151 X 3,169,233 2/ 1965 Schwartz 328--151 X 3,l97,700 7/ 1965 Schwartz et al. 324-77 3,274,576 9/1966 Guignard 340--147 THOMAS B. HABECKR, Primary Examiner.

NEIL C.' READ, Examiner. t

3 5 H; PITTS, Assistant Examiner. 

